VPN for Macintosh on Windows Network

Hello, I wish to add my Macintosh G4 Powerbook with OSX v.
10.3.8 to a corporate Windows network. The IT people at the
company don’t support Macs, so I hope one of you cyber-
experts can help me with the settings. They use Nortel
Networks Contivity VPN Client V04_65.18. Can I connect into
this using my OSX settings?

I’m a non-IT guy, so thanks for answering in simple language!